Generally, a wind turbine includes a tower, a nacelle mounted on the tower, and a rotor coupled to the nacelle. The rotor generally includes a rotatable hub and a plurality of rotor blades coupled to and extending outwardly from the hub. Each rotor blade may be spaced about the hub so as to facilitate rotating the rotor to enable kinetic energy to be converted into usable mechanical energy, which may then be transmitted to an electric generator disposed within the nacelle for the production of electrical energy. Typically, a gearbox is used to drive the electric generator in response to rotation of the rotor. For instance, the gearbox may be configured to convert a low speed, high torque input provided by the rotor to a high speed, low torque output that may drive the electric generator.
The gearbox generally includes a gearbox housing containing a plurality of gears (e.g., planetary, ring and/or sun gears as well as non-planetary gears) connected via one or more planetary carriers and bearings for converting the low speed, high torque input of the rotor shaft to a high speed, low torque output for the generator. In addition, each of the gears rotates about a pin shaft arranged within the one or more planetary carriers. Lubrication systems are often used within the gearbox to circulate oil therethrough, thereby decreasing the friction between the components of the gearbox as well as providing cooling for such components. In addition, the oil is configured to provide corrosion protection while also flushing debris from the lubricated surfaces.
Deformation of many of the gearbox components results in a non-ideal load distribution between the gears. Though all loaded components deform under load, deformation of interfaces between the components is more difficult to predict. The pin shafts of the gearbox therefore often require extensive machining. More particularly, the pin-end connections of the pin shafts, which are loaded in bending, can be problematic by design. Thus, such gearbox components can experience an uneven load distribution.
Accordingly, an improved gearbox assembly for a wind turbine that addresses the aforementioned issues would be welcomed in the art.